1. Field of the Invention
The present invention relates to novel methods of using human myeloid progenitor inhibitory factor-1 (MPIF-1) polypeptide (previously termed MIP-3 and chemokine xcex28 (CKxcex28 or ckb-8)), as well as isolated polynucleotides encoding MPIF-1. Also provided are vectors, host cells and recombinant methods for producing MPIF-1.
2. Related Art
Chemokines, also referred to as intercrine cytokines, are a subfamily of structurally and functionally related cytokines. These molecules are 8-14 kd in size. In general, chemokines exhibit 20% to 75% homology at the amino acid level and are characterized by four conserved cysteine residues that form two disulfide bonds. Based on the arrangement of the first two cysteine residues, chemokines have been classified into two subfamilies, alpha and beta. In the alpha subfamily, the first two cysteines are separated by one amino acid and hence are referred to as the xe2x80x9cCxe2x80x94Xxe2x80x94Cxe2x80x9d subfamily. In the beta subfamily, the two cysteines are in an adjacent position and are, therefore, referred to as the xe2x80x94Cxe2x80x94Cxe2x80x94 subfamily. Thus far, at least eight different members of this family have been identified in humans.
The intercrine cytokines exhibit a wide variety of functions. A hallmark feature is their ability to elicit chemotactic migration of distinct cell types, including monocytes, neutrophils, T lymphocytes, basophils and fibroblasts. Many chemokines have proinflammatory activity and are involved in multiple steps during an inflammatory reaction. These activities include stimulation of histamine release, lysosomal enzyme and leukotriene release, increased adherence of target immune cells to endothelial cells, enhanced binding of complement proteins, induced expression of granulocyte adhesion molecules and complement receptors, and respiratory burst. In addition to their involvement in inflammation, certain chemokines have been shown to exhibit other activities. For example, macrophage inflammatory protein I (MIP-1) is able to suppress hematopoietic stem cell proliferation, platelet factor-4 (PF-4) is a potent inhibitor of endothelial cell growth, Interleukin-8 (IL-8) promotes proliferation of keratinocytes, and GRO is an autocrine growth factor for melanoma cells.
In light of the diverse biological activities, it is not surprising that chemokines have been implicated in a number of physiological and disease conditions, including lymphocyte trafficking, wound healing, hematopoietic regulation and immunological disorders such as allergy, asthma and arthritis. An example of a hematopoietic lineage regulator is MIP-1. MIP-1 was originally identified as an endotoxin-induced proinflammatory cytokine produced from macrophages. Subsequent studies have shown that MIP-1 is composed of two different, but related, proteins MIP-1xcex1 and MIP-1xcex2. Both MIP-1xcex1 and MIP-1xcex2 are chemo-attractants for macrophages, monocytes and T lymphocytes. Interestingly, biochemical purification and subsequent sequence analysis of a multipotent stem cell inhibitor (SCI) revealed that SCI is identical to MIP-1xcex2. Furthermore, it has been shown that MIP-1xcex2 can counteract the ability of MIP-1xcex1 to suppress hematopoietic stem cell proliferation. This finding leads to the hypothesis that the primary physiological role of MIP-1 is to regulate hematopoiesis in bone marrow, and that the proposed inflammatory function is secondary. The mode of action of MIP-1xcex1 as a stem cell inhibitor relates to its ability to block the cell cycle at the G2S interphase. Furthermore, the inhibitory effect of MIP-1xcex1 seems to be restricted to immature progenitor cells and it is actually stimulatory to late progenitors in the presence of granulocyte Hmacrophage-colony stimulating factor (GM-CSF).
Murine MIP-1 is a major secreted protein from lipopolysaccharide stimulated RAW 264.7, a murine macrophage tumor cell line. It has been purified and found to consist of two related proteins, MIP-1xcex1 and MIP-1xcex2.
Several groups have cloned what are likely to be the human homologs of MIP-1xcex1 and MIP-1xcex2. In all cases, cDNAs were isolated from libraries prepared against activated T-cell RNA.
MIP-1 proteins can be detected in early wound inflammation cells and have been shown to induce production of IL-1 and IL-6 from wound fibroblast cells. In addition, purified native MIP-1 (comprising MIP-1, MIP-1xcex1 and MIP-1xcex2 polypeptides) causes acute inflammation when injected either subcutaneously into the footpads of mice or intracisternally into the cerebrospinal fluid of rabbits (Wolpe and Cerami, FASEB J. 3:2565-73 (1989)). In addition to these proinflammatory properties of MIP-1, which can be direct or indirect, MIP-1 has been recovered during the early inflammatory phases of wound healing in an experimental mouse model employing sterile wound chambers (Fahey, et al. Cytokine, 2:92 (1990)). For example, PCT application U.S. Ser. No. 92/05198 filed by Chiron Corporation, discloses a DNA molecule which is active as a template for producing mammalian macrophage inflammatory proteins (MIPs) in yeast.
The murine MIP-1xcex1 and MIP-1xcex2 are distinct but closely related cytokines. Partially purified mixtures of the two proteins affect neutrophil function and cause local inflammation and fever. MIP-1xcex1 has been expressed in yeast cells and purified to homogeneity. Structural analysis confirmed that MIP-1xcex1 has a very similar secondary and tertiary structure to platelet factor 4 (PF-4) and interleukin 8 (IL-8) with which it shares limited sequence homology. It has also been demonstrated that MIP-1xcex1 is active in vivo to protect mouse stem cells from subsequent in vitro killing by tritiated thymidine. MIP-1xcex1 was also shown to enhance the proliferation of more committed progenitor granulocyte macrophage colony-forming cells in response to granulocyte macrophage colony-stimulating factor. (Clemens, J. M. et al., Cytokine 4:76-82 (1992)).
The olypeptide of the present invention, MPIF-1(sometimes also referred to as MIP-3 and Ckxcex2-8), is a new member of the s chemokine family based on the amino acid sequence homology.
In accordance with one aspect of the present invention, there are provided novel methods of preventing or treating injury to cells, tissues and organs using full length or mature MPIF-1 polypeptides, as well as biologically active, diagnostically useful or therapeutically usefully fragments, analogs and derivatives thereof.
In another aspect, the invention provides methods of treatment or prevention using isolated polynucleotides encoding MPIF-1 polypeptides. The MPIF-1 of the present invention is preferably of animal origin, and more preferably of human origin.
The invention also provides MPIF-1 polypeptides and isolated polynucleotides (DNA or RNA) encoding such polypeptides, including mRNAs, DNAs, cDNAs, genomic DNA as well as biologically active and diagnostically or therapeutically useful fragments, analogs and derivatives thereof.
MPIF-1 Polynucleotides. The present invention also provides isolated nucleic acid molecules comprising, or alternatively consisting of, a polynucleotide encoding the MPIF-1 polypeptide having the amino acid sequence shown in FIG. 1 (SEQ ID NO:2) or the amino acid sequence encoded by the cDNA clone deposited as ATCC Deposit Number 75676 on Feb. 9, 1994. The nucleotide sequence determined by sequencing the deposited MPIF-1 clone, which is shown in FIG. 1 (SEQ ID NO:1), contains an open reading frame encoding a polypeptide of 120 amino acid residues, with a leader sequence of about 21 amino acid residues, and a predicted molecular weight for the mature protein of about 11 kDa in non-glycosylated form, and about 11-14 kDa in glycosylated form, depending on the extent of glycoslyation. The amino acid sequence of the mature MPIF-1 protein is shown in FIG. 1 (SEQ ID NO:2).
Thus, one aspect of the invention provides an isolated nucleic acid molecule comprising, or alternatively consisting of, a polynucleotide having a nucleotide sequence selected from the group consisting of: (a) a nucleotide sequence encoding an MPIF-1 polypeptide having the complete amino acid sequence in FIG. 1 (SEQ ID NO:2); (b) a nucleotide sequence encoding the MPIF-1 polypeptide having the complete amino acid sequence in FIG. 1 (SEQ ID NO:2) but minus the N-terminal methionine residue; (c) a nucleotide sequence encoding the mature MPIF-1 polypeptide having the amino acid sequence at positions 22-120 in FIG. 1 (SEQ ID NO:2); (d) a nucleotide sequence encoding the MPIF-1 polypeptide having the complete amino acid sequence encoded by the cDNA clone contained in ATCC Deposit No. 75676; (e) a nucleotide sequence encoding the mature MPIF-1 polypeptide having the amino acid sequence encoded by the cDNA clone contained in ATCC Deposit No. 75676; and (f) a nucleotide sequence complementary to any of the nucleotide sequences in (a), (b), (c), (d), or (e) above.
MPIF-1 Polynucleotide Variants. The present invention further relates to variants of the hereinabove described polynucleotides which encode for fragments, analogs and derivatives of the polypeptide having the deduced amino acid sequence of FIG. 1 (SEQ ID NO:2) or the polypeptides encoded by the cDNA of the deposited clone(s). The variants of the polynucleotides can be a naturally occurring allelic variant of the polynucleotides or a non-naturally occurring variant of the polynucleotides.
Homologous MPIF-1 Polynucleotides. Further embodiments of the invention include isolated nucleic acid molecules that comprise a polynucleotide having a nucleotide sequence at least 95%, 96%, 97%, 98% or 99% identical, to any of the nucleotide sequences in (a), (b), (c), (d), (e), or (f), above, or a polynucleotide which hybridizes under stringent hybridization conditions to a polynucleotide in (a), (b), (c), (d), (e), or (f), above. These polynucleotides which hybridize do not hybridize under stringent hybridization conditions to a polynucleotide having a nucleotide sequence consisting of only A residues or of only T residues.
Nucleic Acid Probes. In accordance with yet another aspect of the present invention, there are also provided nucleic acid probes comprising, or alternatively consisting of, nucleic acid molecules of sufficient length to specifically hybridize to the MPIF-1 nucleic acid sequences.
Recombinant Vectors, Host Cells and Expression. The present invention also relates to recombinant vectors, which include the isolated nucleic acid molecules of the present invention, and to host cells containing the recombinant vectors, as well as to methods of making such vectors and host cells and for using them for production of MPIF-1 polypeptides or peptides by recombinant techniques.
MPIF-1 Polypeptides. The invention further provides an isolated MPIF-1 polypeptide having an amino acid sequence selected from the group consisting of: (a) the amino acid sequence of the MPIF-1 polypeptide having the complete 120 amino acid sequence, including the leader sequence shown in FIG. 1 (SEQ ID NO:2); (b) the amino acid sequence of the MPIF-1 polypeptide having the complete 120 amino acid sequence, including the leader sequence shown in FIG. 1 (SEQ ID NO:2) but minus the N-terminal methionine residue; (c) the amino acid sequence of the mature MPIF-1 polypeptide (without the leader) having the amino acid sequence at positions 22-120 in FIG. 1 (SEQ ID NO:2); (d) the amino acid sequence of the MPIF-1 polypeptide having the complete amino acid sequence, including the leader, encoded by the cDNA clone contained in ATCC Deposit No. 75676; and (e) the amino acid sequence of the mature MPIF-1 polypeptide having the amino acid sequence encoded by the cDNA clone contained in ATCC Deposit No. 75676.
Homologous MPIF-Polypeptides. Polypeptides of the present invention also include homologous polypeptides having an amino acid sequence with at least 95% identity to those described in (a), (b), (c), (d), or (e) above, as well as polypeptides having an amino acid sequence at least 95%, 96%, 97%, 98% or 99% identical to those above.
MPIF-1 Epitope Bearing Polypeptides and Encoding Polynucleotides. An additional embodiment of this aspect of the invention relates to a peptide or polypeptide which has the amino acid sequence of an epitope-bearing portion of an MPIF-1 polypeptide having an amino acid sequence described in (a), (b), (c), (d), or (e), above. Peptides or polypeptides having the amino acid sequence of an epitope-bearing portion of an MPIF-1 polypeptide of the invention include portions of such polypeptides with at least six or seven, preferably at least nine, and more preferably at least about 30 amino acids to about 50 amino acids, although epitope-bearing polypeptides of any length up to and including the entire amino acid sequence of a polypeptide of the invention described above also are included in the invention.
An additional nucleic acid embodiment of the invention relates to an isolated nucleic acid molecule comprising, or alternatively consisting of, a polynucleotide which encodes the amino acid sequence of an epitope-bearing portion of an MPIF-1 polypeptide having an amino acid sequence in (a), (b), (c), (d), or (e), above.
MPIF-1 Antibodies. In accordance with yet a further aspect of the present invention, there is provided an antibody against such polypeptides. In another embodiment, the invention provides an isolated antibody that binds specifically to an MPIF-1 polypeptide having an amino acid sequence described in (a), (b), (c), (d), or (e), above.
The invention further provides methods for isolating antibodies that bind specifically to an MPIF-1 polypeptide having an amino acid sequence as described herein. Such antibodies are useful diagnostically or therapeutically as described below.
MPIF-1 Antagonists and Methods. In accordance with yet another aspect of the present invention, there are provided antagonists or inhibitors of such polypeptides, which can be used to inhibit the action of such polypeptides, for example, in the treatment of arteriosclerosis, autoimmune and chronic inflammatory and infective diseases, histamine-mediated allergic reactions, hypereosinophilic syndrome, silicosis, sarcoidosis, inflammatory diseases of the lung, inhibition of IL-1 and TNF, aplastic anaemia, and myelodysplastic syndrome. Alternatively, such polypeptides can be used to inhibit production of IL-1 and TNF-xcex1, to treat aplastic anemia, myelodysplastic syndrome, asthma and arthritis.
Diagnostic Assays. In accordance with still another aspect of the present invention, there are provided diagnostic assays for detecting diseases related to the underexpression and overexpression of the polypeptides and for detecting mutations in the nucleic acid sequences encoding such polypeptides.
In accordance with yet another aspect of the present invention, there is provided a process for utilizing such polypeptides, or polynucleotides encoding such polypeptides, as research reagents for in vitro purposes related to scientific research, synthesis of DNA and manufacture of DNA vectors, for the purpose of developing therapeutics and diagnostics for the treatment of human disease.
The present invention also provides a screening method for identifying compounds capable of enhancing or inhibiting a cellular response induced by an MPIF-1 polypeptide, which involves contacting cells which express the MPIF-1 polypeptide with the candidate compound, assaying a cellular response, and comparing the cellular response to a standard cellular response, the standard being assayed when contact is made in absence of the candidate compound; whereby, an increased cellular response over the standard indicates that the compound is an agonist and a decreased cellular response over the standard indicates that the compound is an antagonist.
For a number of disorders, it is believed that significantly higher or lower levels of MPIF-1 gene expression can be detected in certain tissues or bodily fluids (e.g, serum, plasma, urine, synovial fluid or spinal fluid) taken from an individual having such a disorder, relative to a xe2x80x9cstandardxe2x80x9d MPIF-1 gene expression level, i. e., the MPIF-1 expression level in tissue or bodily fluids from an individual not having the disorder. Thus, the invention provides a diagnostic method useful during diagnosis of a disorder, which involves: (a) assaying MPIF-1 gene expression level in cells or body fluid of an individual; (b) comparing the MPIF-1 gene expression level with a standard MPIF-1 gene expression level, whereby an increase or decrease in the assayed MPIF-1 gene expression level compared to the standard expression level is indicative of a disorder. Such disorders include leukemia, chronic inflammation, autoimmune diseases, solid tumors, and toxicity from radiation and chemotherapy.
Pharmaceutical Compositions. The present invention also provides, in another aspect, pharmaceutical compositions comprising at least one of an MPIF-1 polynucleotide, probe, vector, host cell, polypeptide, fragment, variant, derivative, epitope bearing portion, antibody, antagonist, or agonist.
Therapeutic Methods. In accordance with yet a further aspect of the present invention, there is provided a process for utilizing such polypeptides, or polynucleotides encoding such polypeptides for therapeutic purposes, for example, to protect bone marrow stem cells from chemotherapeutic agents during chemotherapy, to remove leukemic cells, to stimulate an immune response, to regulate hematopoiesis and lymphocyte trafficking, treatment of psoriasis, solid tumors, to enhance host defenses against resistant and acute and chronic infection, and to stimulate wound healing.
An additional aspect of the invention is related to a method for treating an individual in need of an increased level of MPIF-1 activity in the body comprising administering to such an individual a composition comprising a therapeutically effective amount of an isolated MPIF-1 polypeptide of the invention or an agonist thereof, respectively.
A still further aspect of the invention is related to a method for treating an individual in need of a decreased level of MPIF-1 activity in the body comprising, administering to such an individual a composition comprising a therapeutically effective amount of an MPIF-1 antagonist.
These and other aspects of the present invention should be apparent to those skilled in the art from the teachings herein.